Google Earth Pro users may be happy to learn that the user guide has a section devoted to movie maker tips. By following these suggestions, you can make outstanding movies with much less hassle.
Perhaps the most important thing to do before recording is to maximize the performance of your computer. You can do this by closing all other applications, unchecking all layers in Google Earth except terrain (and 3D buildings if necessary) and downloading the latest video driver for your computer. You can also try adjusting texture quality as this can affect both performance and visual quality of your video.
If you are still have questions, try the Google Earth Pro group.